Lifestyle changes and risk of cancer: experience from the Swedish women's lifestyle and health cohort study

We investigated this issue in the Swedish Women's Lifestyle and Health Cohort Study. We included 29,930 women. From 1991/92 to 2003, median age changed from 40.0 to 51.7 years, alcohol consumption from 2.5 to 4.7 grams/day, BMI from 22.7 to 24.5 kg/m², proportion of current smokers from 31.0 to 20.6% and women reporting high physical activity from 27.2 to 37.0%. Women who quit smoking had lower risk of smoking-related cancers compared to women who continued (hazard ratio (HR) 0.74). Women who reduced their weight by more than 5%, compared to women with stable weight, had lower risk of breast cancer (HR 0.49). Among women with score of 0-2 in 1992/93, those who improved to 3-4 had lower risk of lifestyle-related cancers compared to women who did not (HR 0.81). Healthy lifestyle changes, particularly smoking cessation and weight reduction, were associated with a decreased risk of cancer